Add in-tree mspec and ruby/spec

* For easier modifications of ruby/spec by MRI developers.
* .gitignore: track changes under spec.
* spec/mspec, spec/rubyspec: add in-tree mspec and ruby/spec.
  These files can therefore be updated like any other file in MRI.
  Instructions are provided in spec/README.
  [Feature #13156] [ruby-core:79246]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58595 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

spec/rubyspec/core/kernel/lambda_spec.rb

@@ -0,0 +1,86 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../fixtures/classes', __FILE__)
+require File.expand_path('../shared/lambda', __FILE__)
+
+# The functionality of lambdas is specified in core/proc
+
+describe "Kernel.lambda" do
+  it_behaves_like(:kernel_lambda, :lambda)
+
+  it "is a private method" do
+    Kernel.should have_private_instance_method(:lambda)
+  end
+
+  it "creates a lambda-style Proc if given a literal block" do
+    l = lambda { 42 }
+    l.lambda?.should be_true
+  end
+
+  it "returned the passed Proc if given an existing Proc" do
+    some_proc = proc {}
+    l = lambda(&some_proc)
+    l.should equal(some_proc)
+    l.lambda?.should be_false
+  end
+
+  it "checks the arity of the call when no args are specified" do
+    l = lambda { :called }
+    l.call.should == :called
+
+    lambda { l.call(1) }.should raise_error(ArgumentError)
+    lambda { l.call(1, 2) }.should raise_error(ArgumentError)
+  end
+
+  it "checks the arity when 1 arg is specified" do
+    l = lambda { |a| :called }
+    l.call(1).should == :called
+
+    lambda { l.call }.should raise_error(ArgumentError)
+    lambda { l.call(1, 2) }.should raise_error(ArgumentError)
+  end
+
+  it "does not check the arity when passing a Proc with &" do
+    l = lambda { || :called }
+    p = proc { || :called }
+
+    lambda { l.call(1) }.should raise_error(ArgumentError)
+    p.call(1).should == :called
+  end
+
+  it "accepts 0 arguments when used with ||" do
+    lambda {
+      lambda { || }.call(1)
+    }.should raise_error(ArgumentError)
+  end
+
+  it "strictly checks the arity when 0 or 2..inf args are specified" do
+    l = lambda { |a,b| }
+
+    lambda {
+      l.call
+    }.should raise_error(ArgumentError)
+
+    lambda {
+      l.call(1)
+    }.should raise_error(ArgumentError)
+
+    lambda {
+      l.call(1,2)
+    }.should_not raise_error(ArgumentError)
+  end
+
+  it "returns from the lambda itself, not the creation site of the lambda" do
+    @reached_end_of_method = nil
+    def test
+      send(:lambda) { return }.call
+      @reached_end_of_method = true
+    end
+    test
+    @reached_end_of_method.should be_true
+  end
+
+  it "allows long returns to flow through it" do
+    KernelSpecs::Lambda.new.outer.should == :good
+  end
+end
+